<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        /*.outer {*/
        /*    width: 90%;*/
        /*    height: 300px;*/
        /*    display: flex;*/
        /*    flex-direction: column;*/
        /*    background-color: #666666;*/
        /*    margin: 0 auto;*/
        /*}*/

        .d1 {
            height: 150px;
            background-color: antiquewhite;
        }

        .d2 {

            background-color: asff;
        }

        .d3 {
            width: 90%;
            height: 300px;
            background-color: #998877;
            margin: 0 auto;

        }

        .d4 {
            width: 90%;
            height: 30px;
            background-color: dodgerblue;
            margin: 0 auto;
            text-align: center;
        }
    </style>
</head>
<body>


    <!--    <div class="d1">1</div>-->
    <!--    <div class="d2">2</div>-->

    <div class="d3">12345</div>
    <div class="d4">56789</div>

</body>
</html>